ANA KATHERINA ABARCA HERRERA
Índice h a partir de 2011
2
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
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- Evaluation of the Use of Nerve Allograft Preserved in Glycerol(2021) NAKAMOTO, Joao Carlos; WATAYA, Erick Yoshio; NAKAMOTO, Hugo Alberto; SANTOS, Gustavo Bispo; RIBARIC, Ivan; HERRERA, Ana K. A.; FARIA, Jose C. M.Background: We aimed to evaluate the use of nerve allograft preserved in glycerol. We compared the efficiency of glycerol-preserved allografts with autogenous nerve grafting, cryopreserved grafts, and detergent-processed grafts in the axonal regeneration. Secondarily, we evaluated the effectiveness of each preservation method in maintaining the extracellular matrix free of cellular components. Methods: This was a prospective experimental, longitudinal, unblinded, nonrandomized, controlled animal model study. Three different allograft preservation techniques for the repair of sciatic nerve injuries were compared, including cold preservation, glycerol preservation, and detergent preservation. Functional assessment was performed, and histomorphometric analyses were further performed, which enabled the allograft structure evaluation and an estimation of the nerve regeneration efficacy based on the myelinated axons count and on their diameters. Results: After the 14(th) week, all groups were already balanced and similar (P = 0.265): all groups present near-zero SFIs, thus confirming their efficiency in promoting nerve regeneration. In the histomorphometric evaluations, all groups were equivalent, presenting a similar efficiency in nerve regeneration (P = 0.716 and P = 0.577, respectively). Similarly, histomorphometric evaluations showed a reduction in the number of axons and in their diameters, but none of them effectively eliminated all cellular debris. Comparing the groups with each other, the groups preserved in glycerol and detergent solution were similar, both presenting better results than the cooled group. Conclusion: By evaluating the presence of cell debris after the treatment using glycerol, it was found to be similar to the treatment using detergent and significantly better than the cold-preservation treatment.
- Experimental study of histological changes in vascular loops according to the duration of the postoperative period: Application in reconstructive microsurgery(2017) PAULOS, Renata Gregorio; RUDELLI, Bruno Alves; FILIPPE, Renee Zon; SANTOS, Gustavo Bispo dos; HERRERA, Ana Abarca; RIBEIRO, Andre Araujo; REZENDE, Marcelo Rosa de; HSIANG-WEI, Teng; MATTAR- JR., RamesOBJECTIVES: To analyze the histological changes observed in venous grafts subjected to arterial blood flow as a function of the duration of the postoperative period to optimize their use in free flap reconstructions. METHOD: Twenty-five rats (7 females and 18 males) underwent surgery. Surgeries were performed on one animal per week. Five weeks after the first surgery, the same five animals were subjected to an additional surgery to assess the presence or absence of blood flow through the vascular loop, and samples were collected for histological analysis. This cycle was performed five times. RESULTS: Of the rats euthanized four to five weeks after the first surgery, no blood flow was observed through the graft in 80% of the cases. In the group euthanized three weeks after the first surgery, no blood flow was observed in 20% of the cases. In the groups euthanized one to two weeks after the first surgery, blood flow through the vascular loop was observed in all animals. Moreover, intimal proliferation tended to increase with the duration of the postoperative period. Two weeks after surgery, intimal proliferation increased slightly, whereas strong intimal proliferation was observed in all rats evaluated five weeks after surgery. CONCLUSION: Intimal proliferation was the most significant change noted in venous grafts as a function of the duration of the postoperative period and was directly correlated with graft occlusion. In cases in which vascular loops are required during free flap reconstruction, both procedures should preferably be performed during the same surgery.
- Reduction of Morbidity With a Reverse-Flow Sural Flap: A Two-Stage Technique(2018) REZENDE, Marcelo Rosa de; SAITO, Mateus; PAULOS, Renata Gregorio; RIBAK, Samuel; HERRERA, Ana Katherina Abarca; CHO, Alvaro Baik; MATTAR JR., RamesThe reverse sural flap has often been used for cutaneous coverage of the distal region of the leg and ankle. When the flap is performed in 2 stages, the vascular pedicle is exteriorized and later resected. Our goal was to assess the reverse sural flap performed in 2 stages regarding its viability and low morbidity along the flap-donor area. Eleven patients with cutaneous coverage loss found in the area between the distal third of the leg and ankle underwent cutaneous coverage surgery with a reverse-flow sural flap with an exteriorized pedicle, without violation of the skin between the base of the flap pedicle to the margin of the wound. After a minimum period of 15 days with flap autonomy, the pedicle was resected. The flap dimensions, its viability before and after the pedicle ligature, and the distance from the intact skin between the flap base and the margin of the wound were evaluated. Any losses were measured as a percentage of the total flap size. The respective length and width of the flap were a mean average of 7.45 cm x 4.18 cm. All the flaps survived. Partial loss of the flap occurred in 3 patients, ranging from 20% to 30%. The mean average distance of the intact skin between the pedicle base and the margin of the wound was 5.59 (range 4 to 8) cm. Our results showed that the 2-stage reverse sural flap ensures good flap survival and low morbidity.